首先请阅读下列图片及文字说明：
A． Drop-Bar Road Bikes
Generally lighter in weight than the typical mountain or comfort bike，road bikes are good for multiple pavement uses including fitness riding，commuting，long-distance/event rides，touring and racing．
Drop-bar handlebars are lightweight and aerodynamic and are a better choice if you want to go faster or are more concerned with efficiently transferring your energy into making the bike move forward． They also allow for a greater number of riding and hand positions than flat-bars．Their more aerodynamic riding position (bent over at the waist) may put more strain on your back if you are less flexible．
B． Flat-Bar Road Bikes
Flat-bar handlebars combine the efficiency of drop-bar road bikes with a slightly more upright riding position．This allows you to sit up in a higher and more relaxed position so you can better see the road and potential risks．An upright position also reduces strain on your hands，wrists and shoulders．This increased versatility comes with the tradeoff of being slightly less efficient (from an aerodynamic standpoint) than the typical drop-bar road bike．
C． Hardtail Mountain Bikes
Mountain Bikes are best for dirt or rocky trails and gravel roads; they are OK for pavement too (with tire change)．
Hardtail bikes feature a front suspension fork and a rigid back with no rear suspension shocks．This type of mountain bike is much less expensive and lighter in weight than a typical full-suspension mountain bike．A hardtail is the more versatile choice if you plan to use it for both paved and unpaved surfaces．The tradeoffs from a full-suspension mountain bike? A hardtail is less able to safely handle more technical singletrack trails，provides less overall shock absorption and，in some situations，delivers less rear wheel traction．
D． Full-Suspension Mountain Bikes
Full-suspension mountain bikes have both front and rear suspension shocks making them ideal for backcountry trails or technical (steep，bumpy，twisty) singletrack．They also stand up to more aggressive riding including jumps or drops of up to 5 feet．As mentioned above，full-suspension bikes are more expensive and generally heavier than hardtail bikes．
E．Folding bikes
These bikes can be folded up and placed in a carrying bag，which makes them handy for commuters with limited storage space at home or the office．They are lightweight yet strong and can be folded up quickly and easily．Folding bikes are also a good choice for those who want to travel with their bike．
F．Electric-assist bikes
These bikes feature a battery-powered motor that can help you climb hills easily or make your commute less strenuous．Built-in sensors can monitor how much pressure you're putting on the pedals and then apply battery power accordingly．
以下是一些用户信息，请把图片与相关介绍匹配起来。Tom is a bike lover．He wants to buy a road bike that can go fast on the road． Speed is important but it is more important for him to see the road and stay safe，since the road on which he rides is often full of traffic．
Jack is an office worker．Every day he goes to work by subway．There is still a long way from where he lives to the subway station，so he decides to buy a bike，which can be easily put at home，on the subway train and his office．
Peter loves making long-distance journey by bike．When travelling，he has to climb hills or ride on rocky trails，which makes him too tired to go．He wants to continue his journey even when he is tired，but he doesn’t want to travel by car or ride his motorbike．
Mark is a bike enthusiast who often rides in the mountainous areas．Unfortunately，his bike was damaged when he was riding on the mountain．Now he is going to buy a new mountain bike．Being a rich man，Mark doesn’t care about the price of the bike，but it must be tough and flexible enough to jump and drop on the mountain road．
Jim needs a new mountain bike that can be ridden on both paved and unpaved surfaces．It doesn’t need to be too expensive．He hopes to buy a bike that is lighter in weight than a typical full-suspension mountain bike